Denyof



R. A. FESSENDENI v APPARATUS FOR DIRECTIVE SIGNALING. APPLICATION FILED056.26. 1318.

1,34%,56. .Fatented Aug. 10,1920.

2 SHEETS-SHEET I- WWM @MLLWW R. A. FESSENDEN.'

APPARATUSTOR DIRECTIVE SIGNALING.

APPLIICATION FILED M026, 1918.

Patented Aug; m mm 2 SHEETS-SHEET 2.

INTOR.

ATTORNEYS generally speaking, as sound 7 7. soft rubber or leadin aentree stares PATENT orrics.

REGINALD A FESSE'NDEN,

RINE SIGNAL COMPANY,

. APPARATUS FOR 0:? BROOKLINE, MASSACHUSETTS,

or PORTLAND, MAINE,

AS'SIGNQR To SUBMA- n conromrrou or MAINE.

DIRECTIVE sicmsnmc.

Application filed To all whom it may concern:

Be it known that I, REGINALD A.'Fnssnn- DEN,0f Brookline, in the county0 Norfolk and State of Massachusetts, a citizen of the United States,have invented a new an useful Improvement in A paratus for DirectiveSignaling, of which the following is a specification.

This application is a continuation of application Serial No. 186,627,filed August 16, 1917 so far as may relate to similar matter.

My invention-relates to the transmission-.. and receipt of energy andmore particularly to signaling and still more particularly todirectional signaling, especially the location of submarines andsubmarine signaling Sta tions and also of aeroplanes.

The object of my invention is to improve the acoustic efiiciency of thesending an receiving energy an more especially to 1mprove the efliciencyof signaling and still more to improve the efiiciency of apparatus andmethods for locating submarine signaling stations and Submarines. usedon shipboard or otherwise. Figure 1 accompanying this specilil-ationillustrates, partly diagrammatically, apparatus adapted for carrying outmy invention. Fig. 2 is a diagram described below.

In the figure 33 is a vessel, for example of the destroyer type, 32 arethe compartments of the forepeak or oil tanks of the torpedo destroyer,though they may be fl ui d containers otherwise located, according tocircumstances.

1]. and 12 are sound receiving devices of any suitable kind; for examplemicrophones or stethoscopes or electromagnetic receivers and preferablyoscillators of the kind described in United'Statcs latent'bo. 1,167.36).l shall hereinafter refer to these,

These oscillators are shown as locate on board Sl p and ar" placed inany suitable position v. h ref :nce to each other, either side by sine,or, as shown, back to back in the same tank or adjacent fluid containingtanks, and preferably have their faces perpendicular to of the ship. Asshown, theyare separated by t su-lating screen 13, attached to each 15,16, which may be insulated therefrom by known way.

soundwsereen-v are Bhth' "oscillators and Specification of LettersYatent.

I duce the desired angle as he Patented Aug. 10, 1920.

December '26, 1918. Serial n. 268,231.

mounted on a pivot 29 and can be rotated by any suitable means, as forexample by the handle 17 The sound screen 13, 14: may be construct-- edand shaped in any suitable way to proresult; for example at the end 14the sound screen is shown in curved shape so as to shield to a greaterextent than at the end 13.

I refer so to shape 14 that a sound coming the soundscreen 15, from agiven angle and striking the oscillators will be hear with the samerelative'intensities and phases as a sound coming from the same angleand striking the head of a human being.

The shape of the sound screen plish this is best determined byexperiment,

the shape bein varied until a person listenmp in on telep one receiversattached to the oscillators will; obtain the same change in relativesound intensities in the two receivers when the oscillators are turnedto a certain obtains when he turns his head through the e An importantpoint to note .is that when the oscillators are used in a differentmedium from air,

oscillators apart should preferably near the same relation to thevelocity 0 in such medium, for example water, as the usual distanceapart of the two ears of a human body bears to the velocity of sound inair. For example, if the distance between the cars is 8 inches and thevelocit of sound in air is 1100 feet per secon then if the oscillatorsare immersed in water, in which the velocity of sound is 4400 feet persecond, the oscillators should preferably be laced a little less than 3feet apart. I the oscillators are placed farther apart, as for examplestill further changes are obtained and the sound screen must be extendedstill farther in order to obtain the desired effect on turning theoscillators around on their pivot 29. a

18, 19, 20, 21 are-leads from the oscillators to the indicators shown astelephone receivers 26, 27, which with the other apparatus ma be locatedupon the bridge or other convenient place and are connecte by the headband 28, but are not electrically connected to each other.

33 and 34 are switches for opening 01; mg the lead circuits as desired.

22, 23 are adjustable capacities, and 24,25

closfor example in water,.the distance.

e adjustable inductances. These capacities and inductances have the"function, in addition to their other functions,- that changing theirrelative values the phsseof the sounds reaching the receivers 26,2? canbe altered Without turning the oscillators on their pivot or, if theoscillators are turned on their pivot, the change of phase may beincreased or decreased. 7 I

For example, if a sound is received on the port how, the oscillators maybe either turned by means of the handle 17 until the sound appears tocome from a point perpendicular to and ing the centers of twooscillators, the sound loud to both ears ofthe observer, and the anglethrough which the handle 17 is being moved may be measured and the exactdirection of the sound may he thus deter? mined. Or the oscillators mayhe left stutionary and the condensers 22, 23, or inductthc (liaphraginsof the then being equally ances 24, 25, or both, adjusted until thesound appears dead ahead and the readings of the condensers andinductencos'teken and in this way the exact direction. determined. Orboth oscillators andcondensers and in ductances may be left stationaryand the vessel turned untilthe sound appears to come in dead ahead andthe bow is pointed in the direction of the source of sound.

The tanks 30, 31, 32 are preferably filled either with Water or oil, andwhen the oil is used up, it is preferably replaced with Water.

It is to he noted that 30, 31 and v32, are the oil tanks-or water tanks,and that the chamber. between oil bani: and thehow of the vessel, andthe chamber between; oil tank 32 and the stern of the vessel hot oil orWatertenk chambers, and being filled with air may he called airchambers, and as such do not conduct sound to anything like the sameextent as if they were oil tank chambers, and hence do not conductsounds originating at the bow and stern of the vessel into the oil tanks30, 31 and 352.

The insertion of the oscillators in fluid filled tanks, for exampleforepeelztanks, or,

as'showinin oil tanks, has the great udvans, tags that, as applicant hasdiscovered, it onables the sound to be received nearly as well deadahead as shears.

- For example, withthe installation placed on the S. S. Devereausc thedistance at'which it was possible to send and receive deed ahead was311} miles as against 36 miles aheam. With the installation placed onthe U. S. destroyer Aylwin the Working distance dead ahead was 84% ofthat aheam; Fig. 2 illustrates diagrammatical tests made on aninsulation of this general type,

331 representing the vessel, the dotted line 41 representing the rangeohtaincd'at different angles with oscillators installed in in front ofthe line join or dead asternby making the skin of the ship or the Wallof the tanks or the chem.- her containing the sound receiver so'thst theindex of refraction of the skin the shin or the wall of the tanksrelative to water is unity.

For example, the velocity of sound in water is approximately 44cc feetper second, "while the velocity of sound in steel is approximately1'4',000 feet per second. lonsequently, sounds striking the skin or theship at a small angle are tctelllv reflected and 'do not enter the shipandhfi'ect the oscillators.

I have found, however, that lay loading! the skin of the ship sorefraction of the skin of the ship or the wall of the tanks relative toWater unity not only are water noises but elso'sound posses directlyfrom the signaling station to the oscillator, elm-est es if the skin ofthe ship were not there.

Gne method by which I accomplish this is to electrically weld, orotherwise suit-chi? attach, lumps or disks or plates of lead or othersuitahle msterial, such as tungsten, to the inside of the use materialsuch as nine or tin or tin alloyed with lead, or to e holes punched init, the holes hei s filled lead or brass. Ether menu's suggestthemselves, hut. w Never the arrangernent used, it should be such as tomake the index of refraction of the slain of the ship or thev l" f therelefive to weter equal to n: and ii 37%;. are used, such as disks oficed, she be close together, 2'. 2., the distance between any twoadjacent ones should he epproni mately equal to less then a quarter Wavelength of the sound which is to he received.

This method is also of value as 2% method of eliminating high pitchedsounds which it is not desired to receive, as'sounds whose quarter Wavelength is less than the distance between the Weights may he refractedwhile sounds of longer wave length will be transmitted.

Other arrangements of complish this result and he of my invention Willoccur in the art. 1

I What I claim as my invention is 1. The combination of a ship,aliquidcontaining chamber extending the full Width of the ship,sound-insulatingchambers-l0- cated between said liquid-containin vchamher and the bow and stern of the s lip, and submarine-acoustic meanslocated within the liquid in said chamber.

apparatus to nowithin the scope to those skilled greatly that theindexof lit? messes he eembinas'wn hi 3. a. liqui dcontaining chamberemehdhlg lhe filling chamber extehdin Y the full width of the ship, soadsi suleting ne slnp, sound-insulating chambers located between said.hqmd-centum 1 between said. liquid-uonmining chamher and the bow and.submarine ma]. the bow and stem ol the ship, and finding means locatedwi hin had heme-2001mm means located within liquid,

hefiy of lieuidl 6. The combinatien of a. shig l e liqu'l-ies Thecombination of a shigg a liquid- 'conteining chamber located within saidshlg, ming chamber located withm said ship sound-insulating chambersleuete l between m1 extending the full width of the ship, saidliquid-containing chamber and Zhe bow .mmcl insulhtmg chambers locatedbetween and stem of the ship and extending the lull 823 .51liquid-cmaining chamber and the bow width of the ship, and.submerine-dirscaiohs5 stern of the ship, and. submarine-acousfindingmeans located within said liquid and 1 a means located within saidliquid and on on the longitudinal axis of the ship. 3e we luhgitudihalaxis 0% theship. 7. The combination of a. ship, & liquld- 4L 'lhecembinetiun 0f a. ship, a liquid.- containing chamber extending the fullwidih. eeaaimnihg chamber extending the full width of the shlp,sound-insulating chambers lo- 4e ml the Shift, sound-msulmtmg chambers10- ceted between said liquid-cunteining chamz-ated between saidliquid-centeining her and the bow and stem of the ship, and 342?? andthe bew and stem of the ship, and two submarine-acoustic devicesloeaterl withssbmaxine-directionfindln means iecated in said liquid.EE'ihhill the liquid im said a amber.

The combination of a ship, a. liquid- REGINALD A. FESSENEEN,

"a an

